1,720,965 research outputs found
A complete epidemiological model of a class of genetic diseases
No full textThe epidemiology of X-linked recessive diseases, a class of genetic disorders, has been modeled through a discrete time, structured, non linear mathematical system. The model version presented in this paper completely captures the disease epidemiology as it includes the spread of affected women within a population that has not been considered in other works. Moreover the model allows for de novo mutations (i.e. affected sibling born to unaffected parents) and distinct reproduction rates of individuals depending on their health conditions. Among our contributions, we consider the analytical study of the properties of model’s equilibrium point, that is the distribution of the population among healthy, carrier and affected subjects, and the proof of the stability properties of the equilibrium point through the Lyapunov method. Model sensitivity analysis has been carried out to quantify the influence of model parameters on system response
Optimal operations and load allocation of a power plant equipped with a CCHP feeding power, steam and cold water to an industrial plant
No full textStability and sensitivity analysis of an epidemiological model of genetic diseases
No full textThe epidemiology of X-linked recessive diseases, a class of genetic disorders, has been modeled through a discrete time, structured, mathematical system. The model accounts for both de novo mutations and distinct reproduction rates of procreating couples depending on their health conditions. Relying on Lyapunov’s and LaSalle method, asymptotic stabil- ity properties of model equilibrium points have been proved. Model’ sensitivity analysis has also been carried out to quantify the influence of model’s parameters on system’s response. The model allows to predict the spread over time in the population of any recessive genetic disorder transmitted through the X Chromosome
When sex matters: a complete model of X-linked diseases
No full textX-linked recessive diseases are genetic disorders caused by gene's abnormalities placed on the X chromosome. Due to differences between males and females in sex chromosomes, the transmission mechanisms of these diseases vary in the two sexes. Other than the results of the well-known patterns of inheritance, the current spread of genetic disorders is influenced by spontaneous genetic mutations and individual's reduced reproduction capacities (fertility) conditioned by the disease severity. We developed a structured, continuous-time mathematical model describing how the disease spreads along time; the model accounts for a different fertility of affected individuals and for spontaneous mutations. Through Lyapunov analysis, we gained insights into system's asymptotic behaviour, that is how individual's fitness or spontaneous genetic mutations affect disease's diffusion. To the best of our knowledge, our model is the first one specifically designed to describe X-linked recessive diseases diffusion
Stochastic model predictive control for optimal energy management of district heating power plants
Full text linkIn this paper a control strategy for the optimal energy management of a district heating power plant is proposed. The main goal of the control strategy is to reduce the running costs by optimally managing the boilers, the thermal energy storage and the flexible loads while satisfying a time-varying request and operation constraints. The optimization model includes a detailed modeling of boilers operating constraints, energy thermal energy exchange and the operating modes of the power plant layout. Furthermore, the uncertainty in power demand and renewable power output, as well as in weather conditions, is handled by formulating a two-stage stochastic problem and incorporating it into a model predictive control framework. A simulation evaluation based on the real data and the layout of a Finnish power plant is conducted to assess the performance of our proposed framework
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
